The slow channel syndrome (SCS) is a neuromuscular disorder characterized by fatigability, progressive weakness, and degeneration of the neuromuscular junction. The SCS is caused by missense mutations in the four subunits of the skeletal muscle nAChR. The goal of this proposal is to investigate the mechanisms that lead to the disturbance of the Ca 2+ ionic equilibrium in SCS muscle fibers, and the pathological consequences of this disturbance. To achieve this we will use high-resolution fluorescent imaging in combination with a SCS transgenic murine model. [unreadable] [unreadable]